Apparatus for concentrating solutions.



E. MONTI.

' APPARATUS FOR GONGENTRATING SOLUTIONS.

APPLICATION FILED AUG. 20, 1912.

Patented June 24, 1913.

EUDO MON-TI, 03: TURIN, I'lihLY.

APPARATUS FOR GONGENTEihTING SGLUTIONS.

jectof the King of Italy, and resident of Turin, Italy, have invented -.certain new and 1s a specification.

useful Improvements in Apparatus for C011- centrating Solutions.

The present invention has for its object some improvements in the apparatus described in my U. S. Patent No. 973290 dated October 18, 1910, also in my Patents 7 61387, 893006, 719616, QQhSQO, 9406624, 955659 for operating the above said concentration by treezing, displacing the insoluble substances.

contained in the ice crystals and evaporating in the vacuum the Water left in the mass, for the purpose of concentrating the solutions quickly and economically to such a degree that they may be, according to their nature, either directly disposed of (grape juice concentrated to the consistency of honey and 1 partially crystallized, concentrated must; fruit juice, vegetable extracts, etc.,) or submitted to the last usual operation of crystallization of the sugar (cane sugar, beetroot sugar, crystallizable salts such as carbonate or sulfate of soda, or the like). The apparatus described in my prior patents and consisting'of tanks, coils, straight tubes, etc, are however expensive to construct, require large interchanging surfaces and afford moreover but a limited eiiiciency as while the thickness of the ice layeron said surfaces increases, the number of frigories transmitted through the same diminishes.

' The apparatus forming the principal object of this invention avoids said disadvantages, one of its features being that the interchan ing surfaces onfwhich the freez ing is effected are caused to revolve and the frozen solution stickingthereto is removed in a continuousovayby means of scrapers. A similar apparatus had already been pro posed to avoid the above 'n entioned inconveniences, which *occur'als'o in the ice Works; but itcould not be adopted owing to the great consumption or motive power required for removing the firm ice from the surfaces ,to which it adheres Specification of Letters Patent. Application filed August 20, 1912.

of which the following and owing-also to the Patented June as, rare. Serial No. 716,022.

fact that the ice thus removed in the state of snow from. the said revolving surfaces, though strongly compressed, was opaque, of little consistency and diiiicult to keep. On the contrary, the use of revolving freezing surfaces for alcoholic or sugary solutions, etc, does not show any of the disadvantages above said, as the frozen mass has the consistency of a sherbet (for solutions diluted from 10 to 25%) or of an ice cream (for solutions more concentrated, from 25 to and can be easily removed. More over the frozen mass removed from the re volving surfaces by the scrapers and brought into the displacing tanks for the separation of the more concentrated solutions (according to the process described in my prior Patent No. 761.38?) is in the best conditions for a rapid and complete thawing of the interposed solution. By means of said ro-- toting surfaces it is possible to obtain an output from 530 to 100 kg. of frozen solution for each m of surface in an hour.

In the annexed drawing, Way of example, a constructional form of the present freezing apparatus with revolving surfaces connected with series or" displacing tanks.

Figures 1 and 2 side and front view apparatus. view of a complete plant -for the conccntration of sugary solutions coming from the diffusers, by means of series of the present freezing apparatus and a series of evaporators for boiling in the vacuum, which I heat by means of the water coming out at the temperature of about 25 C. from the condenser of the refrigerating machine and further heated up to about LO-70 3., by causing it to pass through the jacketof a gas or oil engine or through the condenser of a steam engine, also in counter current of the hot gas waste pipes or chimneys.

. The sugary solution leaving the diilusers -1 passes into the interchanger --2- in which the solution coming from the cooled tanks in which the refrigerated juice is allowed to set, circulates in countercurrent and thereafter in the second interchanger are vertical sections in respectively of my said 3 1s a diagrammatic plan I have shown by 3 in which water at the ordinary temperature circulates and finally into the refrigerator 4-- in which the solution 1s brought to a temperature very near its freezing point.

From the refrigerator the solution is conducted into the reservoir 5- having thermically insulated walls, in which the drums -6-- revolve, these latter being horizontally.

disposed (preferably in number of two and rotating in contrary or opposed directions). In the interior of the drums 6 a refrigcrating fluid is caused to circulate, which may be ammonia or any substance having at the ordinary temperature a pressure of vapor above the atmospheric tension (for instance methyl ether or methyl chlorid) and which does not-bite the surface of the cylinders. p

in order to attain the greatest possible efiiciency the cylinder walls must be very thin; it is therefore convenient to make them of a special steel; moreover their surface may be smooth or undulated, as illustrated in the drawing, in order to increase the transmitting surface. Instead of only one reservoir having freezing cylinders 6 it is convenient to employ two, three or more reservoirs, so that the solution, which has become frozen in the first reservoir and separated more concentrated in the underlying displacing tanks, is conveyed into the second reservoir to become again frozen andso on.

The ammonia Wlll be caused to expand successively in the cylinders of the several reservoirs -5 at a lower and lower pressure in order to keep the difference of tern-- perature between the evaporating ammonia and the freezing temperature of the solution becoming more and more concentrated in the successive reservoirs 5- nearly constant. The cylinders -6- are caused to revolve in opposite directions (as indicated by the arrows, Fig. 1) and the frozen solution sticking to them is removed therefrom ina continuous way by the two scrapers 7--, which are disposed inclined in opposite direction between the cylinders, each of them having moreover a double inclination toward their-center (Fig. 2). At the central point common to both scrapers is provided a hole from which a waste or dis charging pipe .-S conveys the frozen solution (removed by the scrapers and sinking by gravitation along the inclined surfaces thereof) into the displacing tanks 9-.

Underneath each reservoir 5 I dispose a series of displacing tanks (preferably in number of four), the tube .-8- having a rubber end, so that it will be possible to cause the'frozen solution to fall successively into the first, second, third and fourth tank 9 to return to the first one, from which meanwhile the concentrated solution has been displaced and the ice removed, and. so on. Each displacing tank -----9- is provided, near its bottom, with a grate --10-- on-which I place a layer of coarse sand or the like l1- through which the more concentrated solution will pass as-it hecomes separated from the ice. The pump '-12--- (Fig. 1) serves to aise this last sowhere they are kept at a low temperature and used to irrigate the ice crystals separated from the solution in the next series of tanks -9- in order to efiect a systematic displacement of the solution still contained in said crystals.

The more concentrated solution dripping from the last displacing tank '9- contains about 45% to 50% crystallizable of sugar and its volume is reduced to about of the ori inal volume of the solu-,

tion. Said solution passes inthe tank "Mi where it is again defecated, and then itis decanted. or filtered in filter ---15-- and con-- ducted intothe first interclmnger -2 where it is again heated. From the inter-- changer ---2- the solution passes into the tank ----l(E--, in. which the juice is saturated with lime, through the pipe -17---, in the carbonation tank -18-- and through the filter --19 into the vacuum concentrating apparatus 20 The reservoirs 5--, having revolving drums 6-, in' the example shown for the preparation of beetroot sugar,.are arranged directly after the diffusers --1, so that the operations of neutralization and carbonatation may be effected on a concentrated solution of about 9, its former volume, th'us obtaining a considerable economy; said. reservoirs however could also be placed after the neutralization and carbonatation --tanks; moreover said "tanks having revolving drums can also be used for freezing any other solution without departing from the principle of this invention. The melting water of the ice separated in the displacing tanks 9 may be conveniently used for a further refrigeration of the gas of the refrigerating machine by using a supplexpentaa';' condenser; the water thus heated may then be used to exhaust a new quantity of material after filtration.

1 to contam a refrigerant ,merged in said reservoir trough situated in I passing through the cooling of the gas or condensation of the solution of the {character The vacuum concentrating apparatus -20- are heated by means of'the water condenser of the refrigerating machine and then, as already said, in the engine jacket, in the steam condenser and in counter current of the hot gas waste pipes or chimneys. The temperature of said water will gradually sink and, if very high degree of vacuum be obtained, the temperature of the water leaving the last concentrator may descend even as low as 15 C. and be used again as refrigerating Water in the condensers. concentrators are refrigerated by means of water at a temperature sinking as far. as 0 (1.; it is thus possible tense in succession the same water for the evaporation of the solution, the condensation of the gas in the condenser of the refrigerating machine, the oil' engine (or the steam steamengine) and then again for the concentration. of the solution and so on, thus effecting al closed cycle of great thermic efficiency andfyery convenient for the countries Where or seasons where one cannot obtain a sufficient quantity of water.

a In the expression solutions used in the claims are intended to be included vegetable, animal and mineral solutions such as musts, wines, liquors, brines', etc.

WhatIclaim is: I r

1. In an apparatus for concentrating a described, a t hermically insulated reservoir for said solutions, a pairi'of hollow cylinders adapted and partially suband revolving in oppositedirections, ed to maintain a constant difference between the temperature of said fluid and the freezing temperature of said solution, a il-shaped the space between said drums and with its ends higher than its 'middle, the sidesofsaid trough forming scrapers for removing the frozensolution adhering to the drums, tanks for receiving the frozen solution and pipe connection froin' the lower part of said trough to said tan (s.

2. In an apparatus for concentrating a solution of the character described; a thermica-lly insulated reservo-ir'for said solu tion, a pair of hollow cylinders adapted to contain a refrigerant and partially submerged in said reservoir and revolving in opposite directions, said refrigerant adapted to maintain a constant difference between the temperature of said fluid and the freezing temperature of said solution, a V-shaped trough situated in ithe space between said drums and with its ends higher than its middle, the} sides of said trough forming scrapers for removingt he frozen solution adhering to the drums, tanks, for receiving The condensers of said,

higher than its said refrigerant adapt-' and revolving in apparatus for concentrating a solutionof the character described, a series of thermically insulated reservoirs for said solution, a pair of hollow cylinders adapted to contain a refrigerant and partially submerged in each of said reservoirs and revolving in opposite directions, said refrig erant adapted to maintain. a constant differ ence between the temperature of said fluid and the, freezing temperature of said solution, a V-shaped trough situated in the space between said drumsand with its ends middle, the sides ,of said scrapers for removing the trough forming frozen solution adhering to the drums, a set of tanks for each reservoir for receiv; ing the frozen solution and pipe connection from the lower part of said trough to said tanks. I

4. In an apparatus for concentrating a solution of the character described, a series of. thermically insulated reservoirs for said solution, a pair of hollow cylinders adapted to contain a refrigerant and partially submerged in each of said reservoirs and revolving'in opposite directions, said refrigerant' adapted to maintain a constant difference between the temperature of said fluid and the freezing temperature of said solution, a V-shaped trough situated in the space between said drums and with its ends higher than its middle, the sides of said trough forming scrapers for removing the frozen solution adhering to the drums, a set of tanks for each reservoir for receiving the frozen solution and pipe connection from the lowcin part of said trough to said tanks; said tanks being provided with a grate near the bottom for a layerof gravel and a pump for drawing ofi the concentrated solution which has passed through the grate; the pumps in the previous set of tanks constructed to deposit said concentrated solution in the next reservoir in the series.

5. In an apparatus for concentrating a solution of the character described, a thermically insulated reservoir for said solu-.

tion, a pair of hollow cylinders adapted to contain a refrigerant and with corrugated sides partially submerged in said reservoir 7 opposite directions, said refrigerant adapted to maintain a constant difference between the, temperature of said fluid and the freezing temperature of said solution, a V-shaped trough situated in the space between said drums'and with its ends higher than its middle, the sides of said trough forming scrapers for removing the frozen solution adhering to the drums, tanks for receiving the frozen solution and pipe 5 connection from the lower part of said trough for selectively connecting the trough with any one "of the tanks.

The foregoing specification si ned at Turin, Kingdom of Italy, this sixth day of August, 1912.

' i EUDO MONTI. Inpresenc'e oi:' V

J OOELYNE SoUBEYRoN, LUG FERR'UCOIS FREVOHACOI. 

